In the manufacture of members having an aperture therein, it is often desired to drill holes in the members, such that the holes are positioned at desired positions relative to the aperture, within acceptable tolerances. It is known to accomplish such manufacturing processes by the use of drilling templates, which are positioned as desired relative to the aperture prior to the drilling operation. It may be understood that accurate positioning of a template relative to an aperture correspondingly results in accurate positioning of the drilled holes relative to the aperture.
It is known in the art to provide tool guiding fixtures, or "jigs", which may be used to position a template as desired relative to a particular aperture. U.S. Pat. No. 2,412,459 to Stull, entitled "TOOL GUIDING FIXTURE" discloses a tool guiding fixture including a template 10, a thumbscrew driven cam member 21 and plunger-like members 32 (see FIG. 3). As the thumbscrew is tightened, cam member 21 is urged upwardly, forcing plunger members 32 outwardly. The plunger members likewise force fingers 38 outwardly and against the inside walls 14 of tubular part 13 such that template 10 is positioned as desired.
U.S. Pat. No. 2,825,143 to Polivka, entitled "TEMPLATE CENTERING JIG" discloses a template centering jig including a template 10 which is centered along two perpendicular axes within a rectangular opening provided by tubing 42. Referring to FIG. 6, centering along the first axis is provided by threaded member 22 which, when tightened, urges actuating pin 34 downwardly, causing locating members 28 and 29 of the centering pin 26 to move apart and outwardly until they engage the inner walls 40 and 41 of the tubing 42. Centering along the second axis is provided by a threaded member 24 (see FIG. 4) which, when tightened, urges actuating a pin 56 downwardly, to urge member 53 and a similarly-shaped unnumbered member outwardly and against the walls of the tubing 42.
Although the methods and apparatuses described in these patents do provide adequate template positioning under certain conditions, they also possess several different disadvantages in that they tend to be relatively complex, and therefore expensive, and also may tend to mar the use of softer metals due to metal-to-metal contact during operation. They may also be relatively difficult to quickly engage and disengage during operation, resulting in disadvantageously excessive labor costs during use.
Therefore, a need has been realized to provide an improved template positioning jig which may be easily operated under a variety of conditions, does not tend to mar the surfaces of the material being processed and may be quickly engaged and disengaged. As always, a need exists to make such devices economical to produce and operate.